This research grant supports the development of a data bank for use in selecting treatment in chronic illness. The data bank will consist of baseline descriptors, data describing mode of treatment and periodic follow-up data describing the patient's status. The data bank is composed of three elements: 1) a bioengineering component investigating the quantitation of biological signals, 2) a computer science component investigating file storage techniques and 3) a clinical component investigating the associations between baseline descriptors, interventions and follow-up events.